SELECTION AND ENRICHMENT OF DIFFERENTIALLY LABELED PLANT-PROTOPLASTS

A fast and efficient method for the selection of plasmamembrane-marked protoplasts via magnetic-associated cell separation (MACS) was develo ped. Isolated mesophyll protoplasts from sunflower (Helianthus annuus L.) were covalently labeled at their plasma membrane with fluoresceine isothiocyanate (FITC) with an efficiency of greater than 95%. They we re subsequently coupled to specific monoclonal antibodies against FITC , which were conjugated to magnetic beads, and mixed with unlabeled hy pocotyl protoplasts. About 95% of the marked mesophyll protoplasts wer e separated by the MACS system with a purity of greater than 80%. Prot oplasts embedded in agarose showed normal dividing activities.